Here is a different way to make room for the downpipe and turbo inlet on a diesel truck.
Last weekend Mike and I started putting the ATS turbo on the 6.9L IDI Ford. One of the challenges we ran into was not being able to bend the firewall back enough to make room for the downpipe. I have a four foot by 1.5-inch square solid steel bar that I was using in conjunction with a two foot pry bar and jack handle. The area that needs bending is very strong. For one thing it is double paneled where the sheet metal joins and it is curved. A hydraulic ram or Porta-Power might work in the tight confines but when I was using the engine block as a base to apply force with the giant pry bar the engine itself started to give about an inch or two. I would rather have been stuck between a rock and a hard place versus a firewall and a slightly movable place.
On this firewall clearance issue I have heard different stories from different people for example:
1. My pipes fit perfectly with no modification.
2. My pipes fit after I slightly bent the lip of the firewall back.
3. Use a 2-inch pipe to bend the firewall back.
4. Use a Porta-Power to bend the firewall back.
5. Get out the Saws All and air hammer and cut a hole then put a panel over it later.
Two Firewall Truths
A. The lip is easy to bend compared to the bend itself.
B. Being under the truck without a lift is a pain.
So here is my plan. I am going to drill a 3/8-inch hole right on the bend where the inlet pipe contacts the firewall. Then about four inches on both sides of the hole I am going to drill a few holes in the bend so the firewall has a place to flex. Then I will get a large slide hammer and bring the firewall back from the comfort of the inside of the cab. I will use different size washers on the end of the slide hammer. First I'll start with large ones so the bend starts as wide as possible. Then I'll use progressively smaller washers to form a channel for the pipes.
I think this might work. The only problem is I hope I can get to where I need to be inside the cab. I think the area is right where the feet would be so it should be accessible I can't wait to try it out.
Here is what we did last weekend:
1. On 83 to 87 6.9L engines the #2 injector line has to be replaced with a replacement that is bent differently to clear the airbox. You have to take all the lines off to get to the #2 line. Well pretty much but you will need to for the next step.
2. The two nipple return line cap on the #7 injector was removed and switched with a one nipple dead end cap. The cross over is now routed from the back fuel line block to the front return line going from the filter to the #1 injector. This modification is needed because the turbo will take up the space in the back of the engine. The ATS kit comes with 1/4-inch fuel line the original lines are smaller so this is something I will have to deal with.
3. We unbolted the rear lifting bracket and added a heat shield in its place.
4. The anti-depression valve was removed from the back of the intake manifold. In its place goes a turbo mount which also acts as a oil drain for the turbo and blocks the little hole in the back of the intake manifold. You have to do this otherwise you would pressurize the crankcase with boost.
5. The anti-depression valve loses its lower hose and plastic bushing. Then it mounts to the driverside intake manifold (you get a new one in the kit). Make sure you leave the emissions stickers on the engine so swap the valve covers if you have to.
Don't have a slide hammer. Auto Zone will rent you one free. The 11-pound version.